This is an Arabic word meaning "to shake off". Contrary to popular belief, engaging in or initiating an intifada does not neccessarily mean violence. There are many nonviolent ways to take part in an intifada.
For example, in protest of the Israeli occupation of the Palestinian territories, the Palestinians often boycott Israeli products, and those who work in Israel have often either quit their jobs or staged peaceful strikes. There are peaceful demonstrations by the Palestinians almost everyday, however they don't get covered by many biased US news agencies such as Fox News. Instead, only only Palestinian youths throwing rocks (which are obviously a lot less deadlier than the guns used by the Israeli soldiers to shoot/scare those rock-throwers) and horrific suicide bombings are shown.
The Intifada was initiated in response to Ariel Sharon's right-wing policies on illegal Israeli settlements in the Palestinian territories.
Islam is a religion of peace (Islam comes from the Arabic word Salaam which means peace, and Muslims always greet each other with the phrase "As Salam Alaikum meaning May Peace be Upon You") and hence there is no room for radicalism.